Apparatus for inspecting printed matters

Claim 3

The apparatus for inspecting printed matters according to claim 1, characterized in that said printed matter (4) includes a first print section (A) bearing an impression of a first ink having at least one reflectivity peak in a visible region and high reflectivity in the invisible region and a second print section (B) bearing an impression of a second ink having at least one reflectivity peak in the visible region.

Claim 4

The apparatus according to claim 2, characterized in that said inspecting means includes a memory area (17) for storing an output signal representing the level of invisible light reflected from said first print section (A), a reference level generator (18) for generating a signal of a reference level, a comparator (19) for comparing the level of a component of the signal stored in said memory area (17) with the reference level, and judging means (20) for judging the printed matter (14) by detecting whether the level of an output from said comparator (19) exceeds the reference level.

Claim 5

The apparatus for inspecting printed matters according to claim 2, characterized in that: said inspecting means includes a memory area (17') for storing an output signal representing the level of invisible light reflected from said second print section (B), a reference level generator for generating (18) a signal of a reference level, a comparator (19') for comparing the level of a component of the signal stored in the memory area (17') with the reference level, and judging means (20) for inspecting the printed matter (4) by detecting whether the level of an output from said comparator (19') exceeds the reference level.

Claim 6

The apparatus for inspecting printed matters according to claim 2, characterized in that: said inspecting means includes a first memory area (17) for storing a first output signal representing the level of invisible light reflected from said first print section (A), a second memory area (17') for storing a second output signal representing the level of invisible light reflected from said second print section (B), means (21) for obtaining the difference between the levels of the components of the first and second output signals stored in said first and second memory areas (17, 17') representing the respective reflectivity, and a judging means (20) for effecting inspection of the printed matter (4) according to the output of said difference obtaining means (21).

Claim 7

The apparatus for inspecting printed matters according to claim 2, characterized in that: said inspecting means includes a first memory area (17)-for storing a first output signal representing the level of invisible light reflected from said first print section (A), a second memory area (17') for storing a second output signal representing the level of invisible light reflected from said second print section (B), a reference level generator (18) for generating reference level signals, first and second comparators (19, 19 1 ) for comparing the levels of the components of the first and second signals stored in the first and second memory areas (17, 17') with the reference level signals, respectively, and judging means (20) for inspecting the printed matter (4) according to the outputs of said first and second comparators (19, 19').

Claim 8

The apparatus for inspecting printed matters according to claim 2, characterized in that: said inspecting means includes a first memory area (17) for storing a first output signal representing the level of invisible light reflected from said first print section (A), a second memory area (17') for storing a second output signal representing the level of invisible light reflected from said second print section (B), means (21) for obtaining the difference between the levels of the components of the first and second output signals stored in said first and second memory areas (17, 17'), a reference level generator (18) for generating reference level signals, first and second comparators (19, 19') for comparing the levels of the components of the first and second signals with the reference level signals, respectively, and judging means (20) for inspecting the printed matter (4) according to the outputs of said difference obtaining means (21) and first and second comparators (19, 19').

Claim 9

The apparatus for inspecting printed matters according to claim 2, characterized in that: both said first and second inks are of chromatic or achromatic color; said means for forming an electric signal includes a blue reflection mirror (36) to which light reflected by said printed matter (4) is coupled, a first photoelectric converter (41) for forming an electric signal representing blue light reflected by said blue reflection mirror (36), a green reflection mirror (37) to which light transmitted through said blue reflection mirror (36) is coupled, a second photoelectric converter (45) for forming an electric signal representing to green light reflected from said green reflection mirror (37), a red reflection mirror (38) to which light transmitted through said green reflection mirror (37) is coupled, a third photoelectric converter (49) for forming an electric signal representing red light reflected by said red reflection mirror (38), a near-infrared filter (30) to which light transmitted through said red reflection mirror (38) is coupled, and a fourth photoelectric converter (33) for forming an electric signal representing near-infrared light transmitted through said near-infrared filter (30); and said inspecting means includes first to fourth memories (57, 55, 53, 51) in which data in the output signals of said first to fourth photoelectric converters (41, 45, 49 and 32) for said first print section (A) are respectively stored, fifth to eighth memories (58, 56, 54, 52) in which data in the output signals of said first to fourth photoelectric converters for said second print section (B) are respectively stored, first to fourth difference circuits (64, 63, 62, 61) for forming respective difference signals between the outputs of said first and fifth memories, between the outputs of said second and sixth memories, between the third and seventh memories and between the fourth and eighth memories, a reference level signal generator (68) for generating reference level signals, first and second comparators (56, 57) to which the outputs of said respective fourth and eighth memories and the reference level signals are supplied, and judging means (74) to which the outputs of said difference circuits (64, 63, 62, 61) and the outputs of said comparators (56, 57) are supplied.

Claim 10

The apparatus for inspecting printed matters according to claim 1, characterized in that said printed matter (4) includes a first print section (A) bearing an impression of a first ink having at least one reflectivity peak in the visible region and at least one reflectivity peak in the invisible region and a second pring section (B) bearing an impression of a second ink having at least one reflectivity peak in the visible region.

Claim 11

The apparatus for inspecting printed matters according to claim 9, characterized in that: said means for irradiating the printed matter with electromagnetic radiation is a lamp (18) for producing electromagnetic radiation in a wavelength region corresponding to the light emission characteristic of said first ink; said means for forming an electric signal includes a near-infrared filter (82) to which light reflected and light emitted by said printed matter (4) are coupled, and a photoelectric converter (84) for generating an electric signal corresponding to light from said filter (82); and said inspecting means includes a memory (87) for storing the electric signal from said photoelectric converter (84), a reference level generator (89) for generating a reference level signal, a comparator (88) to which the output signal from said memory (87) and said reference level signal are supplied, and judging means (90) to which the output of said comparator (88) is supplied.

Claim 12

The apparatus for inspecting printed matters according to claim 1, characterized in that said printed matter (4) includes a first print section (A) bearing an impression of a first ink having a light emission characteristic having at least one peak in the visible region and also at least one peak in the invisible region.

Claim 13

The apparatus for inspecting printed matters according to claim 11, characterized in that: said means for irradiating the printed matter with electromagnetic radiation is a lamp (91) for emitting ultraviolet radiation in a wavelength region corresponding to the light emission characteristic of said first ink; said means for forming an electric signal includes a dichroic mirror (93) to which light from said first print section (A) is coupled and which reflects only visible light, a first photoelectric converter (96) for forming an electric signal corresponding to visible light from said dischroic mirror (93), and a second photoelectric converter (99) for forming an electric signal corresponding to near-infrared radiation transmitted through said dichroic mirror (93); and said inspecting means includes first and second memories (103, 104) for storing the output signals from said respective photoelectric converters (96, 99), a reference signal generator (107) for generating reference level signals, first and second comparators (105, 106) to which the output signals of said respective first and second memories (103, 104) and said reference level signals are supplied, and judging means (105) to which the output signals of said first and second comparators (105, 106) are supplied.

Claim 14

The apparatus for inspecting printed matters according to claim 1, characterized in that said printed matter (4) includes a print section (A) bearing an impression of an ink having a reflectivity peak in a wavelength region (λ 1 ) in the visible range, higher reflectivities than said reflectivity peak in a wavelength region (X 3 ) in the invisible range and lower reflectivities than said reflectivity peak in a wavelength region (a 2 ) between said two wavelength regions.

Claim 15

The apparatus for inspecting printed matters according to claim 13, characterized in that: said means for forming an electric signal includes first extracting means (111, 112) for extracting a high reflectivity component of a first wavelength (X 3 ) in said invisible region from the light reflected from said print section (A), a first photoelectric converter (114) for obtaining an electric'signal corresponding to said first wavelength (X 3 ) component, second extracting means (115, 116) for extracting a component of a second wavelength (X 2 ) from said reflected light, a second photoelectric converter (118) for obtaining an electric signal corresponding to said second wavelength (X 2 ) component from said second extracting means (115, 116), third extracting means (115, 119) for extracting a component of a third wavelength (a l ) from said reflected light, and a third photoelectric converter (121) for forming an electric signal corresponding to said third wavelength (X l ) component from said third extracting means (115, 119); and said inspecting means includes first to third memories (125, 126, 127) for storing the output signals of said respective first to third photoelectric converters (114, 118, 121), first to third difference obtaining means (129, 130, 131) for forming difference signals between respective combinations of the output signals of said first to third memories (125, 126, 127), a reference level generator (135) for generating reference level signals, comparators (132, 133, 134) to which the output signals of said respective first to third memories (125, 126, 127) and said reference level signals are supplied, and judging means (136) to which the outputs of said difference circuits (129 to 131) and the outputs of said comparators (132 to 134) are supplied.

Claim 16

The apparatus for inspecting printed matters according to claim 13, characterized in that: said means for forming an electric signal includes a plurality of photoelectric converters (151 to 158) for forming electric signals representing respective spectral reflectivity characteristics of the printed matter (4); and said inspecting means includes a first memory (170) for storing the output signals from said photoelectric converters (151 to 158), a second memory (173) in which data representing a reference spectral reflectivity characteristic of said printed matter (4) are stored, means (172) for obtaining a difference signal between two spectral reflectivity data successively read out from said respective first and second memories (170, 173), means (174) for accumulating the output of said difference obtaining means (172), and judging means (175) to which the output of said accumulating means (174) is supplied.